The present invention relates to a steel laminate gasket for an internal combustion engine with an engine block protecting device.
In an internal combustion engine, a gasket is installed between two engine blocks for sealing around cylinder holes, water holes, oil holes and so on. Recently, an engine has been developed to provide high power with light weight. For this purpose, an engine size is getting smaller, and a cylinder head is made of an aluminum alloy.
A steel laminate gasket formed of a plurality of steel plates is strong and can securely seal around holes where high pressure is applied. Therefore, a steel laminate gasket has been used for an engine with high power and light weight.
In a steel laminate gasket, in case an area around a hole where high pressure is applied, such as a cylinder hole, is tightly sealed, a wire ring may be incorporated in the steel laminate gasket. A steel laminate gasket 10 with a wire ring 11 is shown in FIG. 1.
The gasket 10 as shown in FIG. 1 is formed of an upper plate 12 with a curved portion 12a and a flange 12b, a lower plate 15, and two inner plates 13, 14. The wire ring 11 is situated adjacent to the curved portion 12a.
In case the gasket 10 is installed between a cylinder head X made of an aluminum alloy and a cylinder block Y made of iron, and is strongly tightened, the cylinder head X as well as the wire ring 11 slightly dent or deform.
While an engine is operating, the engine is slightly vibrating. Therefore, once a cylinder head slightly deforms, the gasket can not seal completely around a hole.
Further, in case a cylinder head deforms, if a cylinder head is removed from a cylinder block, the cylinder head can not be used any more. Even if a new gasket is installed between the cylinder head and cylinder block, complete sealing between the cylinder head and cylinder block can not be made because of the dent of the cylinder head. In order to use the deformed cylinder head, it is required to make the deformed cylinder head flat by cutting the same.
Therefore, an object of the present invention is to provide a steel laminate gasket, which can be tightened strongly without causing damages to the engine blocks.
Another object of the invention is to provide a steel laminate gasket as stated above, wherein an even surface pressure can be applied around a hole to be sealed.
A further object of the invention is to provide a steel laminate gasket as stated above, which can be manufactured easily and economically.
Further objects and advantages of the invention will be apparent from the following description of the invention.